The StoryBots tell their boss, Hap, what they have found out, in order to help answer Coco and Lennon's question of "Why do people look different?".

Hank explains that DNA stores our genetic instructions and illustrates how DNA is structured. He explains the parts of the Double Helix structure and uses a book to put into perspective just how many base pairs are tightly packed in each chromosome.

Hank explains how DNA and three specialized versions of RNA synthesize proteins. He delves into the process of transcription, which involves copying genetic information from DNA to RNA.

Peter gets home after being bitten by a genetically-engineered spider during a school field trip. He falls ill from the spider's venom, and while he's asleep the venom alters his genetic makeup. He wakes up to find his body has changed dramatically overnight.

The Titans try to prevent Robin from fighting Johnny Rancid after he breaks his hand. Robin creates Larry, who is a big fan of Robin's and wants to help him.